Prognostic significance of serum chloride level in heart failure patients with preserved ejection fraction

AIMS: The prognostic value of serum chloride level has been reported primarily in patients with heart failure with reduced ejection fraction, and hence, there is limited evidence in patients of heart failure with preserved ejection fraction (HFpEF). This study was conducted to clarify the relationship between serum chloride level and clinical outcomes in patients with HFpEF with acute decompensated heart failure (ADHF). METHODS AND RESULTS: Patient data were extracted from The Prospective mUlticenteR obServational stUdy of patIenTs with Heart Failure with Preserved Ejection Fraction (PURSUIT HFpEF) study, a prospective multicentre observational registry for ADHF‐HFpEF in Osaka. The data of 870 patients were analysed after excluding patients with in‐hospital death, missing follow‐up data, missing data of serum chloride level, or on chronic dialysis therapy. The primary endpoint of this study was all‐cause mortality. At discharge, right ventricular systolic dysfunction was significantly associated with the lowest tertile of serum chloride level after multivariable adjustment (P = 0.0257). During a mean follow‐up period of 1.8 ± 1.0 years, 186 patients died. Cox multivariable analysis showed that serum chloride level at discharge (P = 0.0017) was independently associated with all‐cause mortality after multivariable adjustment of major confounders, whereas serum sodium level was no longer significant (P = 0.6761). Kaplan–Meier survival curve analysis revealed a significantly increased risk of mortality stratified by the tertile of serum chloride level [29% vs. 19% vs. 16%, P = 0.0002; hazard ratio (HR): 2.09 (95% confidence interval, CI: 1.31 to 3.34), HR: 1.03 (95% CI: 0.65 to 1.64)]. CONCLUSIONS: Serum chloride level was useful for the prediction of poor outcome in ADHF patients with preserved ejection fraction.